Pneumatic punch



Aug. 16,1966 R. G. WILLIAMSON 3,265,355

I PNEUMATIC PUNCH Filed July- 23. 1964 2 Sheets-Sheet 1 v 25 5 DRIVE i 1T7 FIG. 1

7\ SIGNAL SOURCE FIG. 3

FIG. 7

INVENTO ROBERT C. WI MSON A T TORNE Y5 United States Patent 3,266,355 PNEUMATIC PUNCH Robert G. Williamson, Norwalk, Conn, assignor to Sperry Rand Corporation, New York, N.Y., a corporation of Delaware Filed July 23, 1964, Ser. No. 384,697 11 Claims. (Cl. 83-177) The present invention relates to a method and means for punching holes in thin pieces of material. More particularly, the present invention relates to a method and means for punching holes in record media such as cards or tapes, said method and means employing no moving parts other than a working fluid for accomplishing the punching operation.

In card and tape punches of the prior art it has been customary to employ mechanical or electro-mechanical means for punching holes in record media. These devices employ a solid body or punch which is forced through the record medium into a die. The force for driving the punch is usually developed through a mechanical or electro-mechanical linkage. These linkages are in many cases quite complex and costly. Also, they are subject to wear as are the punches, and replacement or adjustment at frequent intervals is required to insure that the holes are cleanly punched.

To avoid the problem of wear inherent in mechanical devices attempts have been made to accomplish punching by means of fluid pressure applied directly to the record medium. In one such device an anvil is disposed in a chamber having an opening adjacent the record medium. A pair of electrodes are disposed in the chamber and a spark discharge is caused to occur thus rapidly heating the entrapped air and causing it to expand. The expanding air is bounded on one side by the anvil and on the other by the record media so that as it expands it forces a portion of the record medium into a die hole. This device has a disadvantage in that it does not produce a cleanly cut hole. The reason for this is that the expanding air exerts the greatest pressure at the center of the area to be punched thus tending to rupture the record medium in this area before it is sheared at the edges of the die hole. There is a further disadvantage in that the electrodes and wiring required in this device do not permit high density packing as required for some record punching operations.

Therefore, an object of this invention is to provide a novel method and apparatus for punching record media, said method and apparatus having none of the disadvan tages enumerated above.

An object of this invention is to provide a method and apparatus for punching a record medium, said method and apparatus producing cleanly cut holes as a result of application of fluid pressure to the medium. The fluid may come from a pneumatic amplifier and is shaped before being directed against the record medium.

An object of this invention is to provide a punch device for punching a record medium, said punch device comprising die means having an aperture therein disposed on one side of the path of the record medium, means defining a fluid chamber having an opening therein disposed on the other side of the record medium opposite said aperture, means for selectively supplying fluid under pressure to the chamber, and shaping means disposed within the chamber for directing the fluid through the opening and against the record medium with a velocity that varies over the width of the aperture.

Birefly, the present invention contemplates the shaping of a charge of pressurized fluid into a jet stream and directing the jet stream toward a die hole. The shape of the jet conforms to the shape of the die hole. Furthermore,

the velocity of the fluid particles in the interior of the jet is less than the velocity of the fluid particles near the exterior of the jet. Therefore, when a record medium is inserted between the jet and the die hole, the greatest pressure or shearing force is exerted on the record medium at the edge of the die hole thus producing a clean shear Without causing rupture of the type described above.

Other objects of the invention and its mode of operation will become apparent upon consideration of the following description and the accompanying drawings in which:

FIGURE 1 is a front view, partly in section, illustrating a punch constructed in accordance with the principles of the present invention;

FIGURE 2 is a fragmentary View taken along the line 2-2 of FIGURE 1;

FIGURE 3 is a diagram illustrating the jet velocity profile and the pressure exerted by the jet on an area to be punched from a record medium;

FIGURE 4 shows a fragment of a record medium surrounding an area to be punched from the record medium;

FIGURE 5 shows a second embodiment of the invention;

FIGURE 6 is a sectional view taken along he line 6-6 of FIGURE 5; and

FIGURE 7 illustrates a modification of the embodiment shown in FIGURE 5.

Referring now to FIGURES 1 and 2, a preferred embodiment of the invention comprises a bed plate 1, a shaping means 3, a die 5, and a signal source 7. Formed within bed plate 1 is a chamber 9 having an opening 11 adjacent the path of a record medium or other workpiece 13. The shaping means 3 is mounted within the chamber and axially aligned with opening 11. The shaping means comprises an upright body having an exterior surface which diverges outwardly in the direction of opening 11 and an upper surface 17 (as viewed in FIGURE 1) which is in the same plane as the surface 15 of the bed plate. The'surface 17 is also circular but has a diameter slightly less than the diameter of opening 11 so that an annular orifice is formed which is bounded on one side by the chamber walls and bounded on the other side by the exterior surface of the upright body.

Although the surface 17 and opening 11 are described herein as having a circular configuration, it is also possible for them to have triangular, rectangular, or other configurations. Regardless of the configuration employed the dimensions of the surface 17 should be less than the corresponding dimensions of opening 11 so that an orifice is formed through which fluid may escape from the chamber. I

The die 5 has formed therein a hole or aperture 19 which is of substantially the same size as opening 11.

Hole 19 is axially aligned with opening 11 but is disposed on the opposite side of the path of the record medium.

:As subsequently explained, means are provided for moving the die away from the record path while the record is being moved into punching position after which the die is moved toward the record path to thus reduce fluid leakage during the punching operation.

In a typical operation source 7 produces a signal in the form of a charge of fluid under pressure each time a hole is to be punched in the record medium. The fluid pressure of the charge must be suflicient to accomplish the punching operation hence theexact value of the fluid pressure employed is dependent upon the thickness of the record medium and the material from which it is made. The charge is conveyed by means of a tube or other suitable conveying means 21 to the chamber 9. As the fluid enters chamber 9 from tube 21 the pressure in the chamber rises rapidly and fluid is forced out of the chamber through the annular opening as a jet stream of fluid particles moving at high velocity.

FIGURE 3 depicts the velocity profile across the'diameter D of opening 11 while the jet flows through the opening. This is also a pressure profile since it corresponds to the pressure exerted by the jet on the area to be punched from the record medium. The velocity of the fluid at or near the center line is almost Zero and increases outwardly from the centerline to a maximum which occurs in the region near the bounding edge of the opennig. Stated differently, the jet which issues from the opening comprises an inner region surrounded by an outer annular region wherein the fluid particles move at a much greater velocity.

Reference is now made to FIGURE 4 which shows the fragment of a record medium immediately surrounding that portion which is to be removed from the record medium during the punching operation. The circle 27 designates the portion to be removed from the record medium while the circle 29 corresponds to the configura tion of surface 17 (FIGURE 1). When the jet strikes the record medium 13 the record medium is forced against die surface 25. Because of hole 19 there is an area of the record medium which is not supported or backed-up by the die. In FIGURE 4 this unsupported area corresponds to the area within circle 27. That portion of the jet having the highest velocity strikes and thus exerts the greatest pressure on the annular region just Within the boundary of this area. In FIGURE 4 this corresponds to the annular region between circles 27 and 29. This pressure exerted against the unsupported area of the record medium shears the record medium around the edge or periphery of the die hole. In FIGURE 4 this shearing takes place along the line of circle 27 since this line defines the separation between the supported and unsupported areas of the record medium.

Since the fluid which strikes the inner portion of the unsupported area is moving at a much lower velocity there is less pressure applied to the inner portion. In FIG- DRE 4 this inner portion corresponds to the area within circle 29. Accordingly, the record medium is not ruptured at or near the center of the unsupported area.

Signal source 7 may comprise any suitable means for producing a stream of fluid each time the record medium is to be punched. It may, for example, comprise a pure fluid amplifier. It is well known that these amplifiers may employ air or another gas or water or another liquid as a working fluid. However, in the present application it is preferable that a gas and more particularly air be used.

The pressure profile shown in FIGURE 3 will vary depending upon the clearance between the record medium and the surfaces 15 and 17 at the time the jet issues from opening 11. If there is no clearance between the record medium and surface 17 then the pressure is zero from the centerline to the outer edge of surface 17. As the clearance between the record medium and surface 17 increases the pressure near the centerline increases 'accordingly. In like manner, the pressure drops abruptly to zero at the edge of hole 11 if there is no clearance between the record medium and surface '15 but decreases less abruptly as the clearance is increased. Both clearances allow leakage from the high pressure region and thus reduce the force avail-able to shear the record medium.

In order to reduce the clearance it is contemplated that some means be provided for alternately raising and lowering the die in synchronism with the movement of the record medium into and out of the punching position. The die is raised in order to permit movement of the record medium into the punching position after which the die is lowered. After the punching operation takes place the die is again raised to permit movement of the record medium. Apparatus for accomplishing these movements is well known in the art hence it is indicated in blockform FIGURES 5 and 6 illustrate a second embodiment of the invention. FIGURE 5 is a sectional view taken through the center of the device and shows the chamber and channel configuration of a fluid amplifier disposed within bed plate 1 for the purpose of intermittently producing a charge of fluid under pressure.

The amplifier has a substantial third dimension and operates on the principle of boundary layer control in the same manner as two dimensional amplifiers of the type described in Patent No. 3,001,698. The amplifier may best be visualized by assuming that the configuration to the left of the centerline in FIGURE 5 is rotated about the centerline through an arc of 360 degrees thus forming a power stream input channel 33 and first and second control input channels 35 and 37 each having an annular configuration. The amplifier has a first output channel 39 which terminates at one end at an annular opening 11' and a second output channel 41 which terminates at an annular opening 42. Output channels 39 and 41 converge to form an interaction chamber 43.

A channel 45 connects at one end with power stream channel 33 and is connected at the other end to a suitable source such as a compressor 46 which continuously supplies fluid under pressure at a substantially constant rate. A reset channel 47 connects at one end with channel 35 and is connected at the other end to a source 48 which produces a fluid signal each time a punching operation is to be terminated. An input channel 49 connects at one end with control channel 37 and has its other end con nected to a signal source 51 which produces a fluid signal each time a punching operation is to be initiated.

Bounded by the output channels 39 and 41 is a body 52. The upper extent of this body is designated 53 and corresponds in function with the jet shaping body 3 shown in FIGURE 1. The chamber 9' is not as clearly defined as the chamber 9 of the previous embodiment since it has the same shape and size as an annular output channel 39. In fact, chamber 9' in this embodiment is nothing more than the downstream portion of channel 39. Die hole 19 is substantially the same size as hole 11.

The basic theory of operation of fluid amplifiers is well known and is described in the aforementioned patent hence a detailed description of the amplifier is not given herein.

Assume that the fluid from source 46 is feeding into channel 33 and that the resulting fluid power jet issuing into chamber 43 is locked on to wall 57 so that it flows out through channel 41. In order to initiate a punching operation source 51 produces a fluid signal which flows through channel 49, spreads out around channel 37, and moves upwardly into chamber 43 to disperse the boundary layer along wall 57 and deflect the power jet into output channel 39. The deflected power jet moves through channel 39 and strikes the record medium over the annular area blocking hole 11. The resulting force shears the record medium around the edge of hole 19 and the chip is blown out.

Source 48 produces a fluid signal to terminate the punching operation. The signal travels through channel 47, spreads out around channel, and enters chamber 43. The fluid disperses the boundary layer along wall 55 and deflects the power jet toward output channel 41 where it again locks on to wall 57.

In FIGURE 5 the hole 19 is shown as being of substantially the same size as hole 11'. Actually, the size of hole 19 depends in part upon the configuration of the Walls of channel 39 and the resulting pressure profile. For example, it is well known that the power jet may be made to lock-on to wall 59 rather than wall 55 in which case the greatest force is exerted on the record medium in the area immediately adjacent the outer surface of body 53. At the same time a lesser force is exerted on the area of the record medium adjacent the end of wall 55 so that there is a tendency to rupture the card before it is sheared. Therefore, in some cases the hole 19 may be made smaller than hole 11' so that the edge of hole 19 is at the region of greatest shearing force. This arrangement is illustrated in FIGURE 7.

The invention has been described in connection with a record medium such as a card or tape of the type employed in computing systems. When utilized in this manner it is obvious that a gaseous fluid, preferably air, be employed as the working medium. In other applications it may be preferable to employ a liquid such as water.

It will be understood that in actual practice the punching mechanisms herein described will be smaller than shown in the accompanying drawings thus permitting a plurality of punches to be arranged over a small area of a record medium. As is usual in such cases each punch may be provided with its own signal source which is selectively actuated when a punching operation is to take place. 'In other applications of the invention to the punching of sheet material it may be desirable to provide a plurality of punches all of which are simulttaneously attenuated from a single signal source.

Obvious modifications of the embodiments herein disclosed may be made without departing from the spirit and scope of the invention as defined by the appended claims.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A punch device for punching a record medium, said punch device comprising: die means having an aperture therein disposed on one side of the path of said record medium; means defining a fluid chamber having an opening therein having the same dimensions as said aperture, said opening being positioned on the other side of said record medium and opposite said aperture; means for selectively supplying fluid under pressure to said chamber; and shaping means disposed within said chamber for directing said fluid through said opening and against said record medium with a velocity that varies over the width of said aperture.

2. A punch device as claimed in claim 1 wherein said shaping means comprises a body positioned along the axis of said aperture and defining with the wall of said chamber an orifice for directing said fluid toward said aperture near its edge.

3. A punch device comprising: means defining a fluid chamber having an opening therein; means for supplying fluid under pressure to said chamber; a body disposed within said chamber, said body extending toward said opening and diverging outwardly in the direction of said opening whereby said fluid emerges from said opening as a high velocity jet stream of fluid particles surrounding slower moving fluid particles; and die means defining a hole of the same size as said jet stream and aligned therewith whereby the fluid particles of highest velocity are directed toward the periphery of said die hole.

4. A punch device as claimed in claim 3 wherein said means for supplying fluid under pressure includes a pure fluid amplifier, and means for selectively actuating said amplifier.

5. A punch device as claimed in claim 3 and further comprising means for positioning a record medium between said opening and said hole whereby said jet stream exerts a shearing force on said record medium at the edge of said die hole.

6. A punch device as claimed in claim 5 wherein said body terminates in the plane of said opening.

7. A punch device as claimed in claim 5 wherein said opening is at least as large as said die hole.

8. A punch device comprising: means defining a fluid chamber having an opening therein; means for supplying fluid under pressure to said chamber; a body disposed within said chamber and extending toward said opening to terminate in the plane of said opening whereby said fluid emerges from said opening as a high velocity jet stream of fluid particles surrounding slower moving fluid particles; and die means defining a hole of the same size as said jet stream and aligned therewith whereby the fluid particles of highest velocity are directed toward the periphery of said die hole.

9. The device of claim 8 wherein said means for supplying fluid under pressure includes a pure fluid amplifier, and means for selectively actuating said amplifier.

10. A punch device comprising: means defining a fluid chamber having an opening therein; means for supplying fluid under pressure to said chamber; a body disposed within said chamber and extending toward said opening whereby said fluid emerges from said opening as a high velocity jet stream of fluid particles surrounding slower moving fluid particles and die means defining a hole of the same size as said jet stream and aligned therewith wherein said opening is at least as large as said die hole whereby the fluid particles of highest velocity are directed toward the periphery of said die hole.

11. The device of claim 10 wherein said means for supplying fluid under pressure includes a pure fluid amplifier, and means for selectively actuating said amplifier.

References Cited by the Examiner UNITED STATES PATENTS 2/1964 Sowers 836 39 X 6/1964 Keahey 83-117 X 

1. A PUNCH DEVICE FOR PUNCHING A RECORD MEDIUM, SAID PUNCH DEVICE COMPRISING: DIE MEANS HAVING AN APERTURE THEREIN DISPOSED ON ONE SIDE OF THE PATH OF SAID RECORD MEDIUM; MEANS DEFINING A FLUID CHAMBER HAVING AN OPENING THEREIN HAVING THE SAME DIMENSIONS AS SAID APERTURE, SAID OPENING BEING POSITIONED ON THE OTHER SIDE OF SAID RECORD MEDIUM AND OPPOSITE SAID APERTURE; MEANS FOR SELECTIVELY SUPPLYING FLUID UNDER PRESSURE TO SAID CHAMBER; AND SHAPING MEANS DISPOSED WITHIN SAID CHAMBER FOR DIRECTING SAID FLUID THROUGH SAID OPENING AND AGAINST SAID RECORD MEDIUM WITH A VELOCITY THAT VARIES OVER THE WIDTH OF SAID APERTURE. 